you're one of the 50 million americans with frequent heartburn. did you know, with prilosec otc, you can stop frequent heartburn before it starts? heartburn happens when stomach acid refluxes, or backs up into the esophagus. this causes the burning sensation in your chest, known as heartburn. with just one pill a day, prilosec otc treats frequent heartburn for 24 hours, providing all-day and all-night protection. here's how it works -- prilosec otc's unique delayed-release system protects the medicine as it passes through the stomach's tough acid. the medicine then gets absorbed into the body, turning off many acid-producing pumps at the source, so less acid is produced. with just one pill a day, you get 24-hour heartburn protection all day and all night, satisfaction guaranteed. trust the number-one doctor-, gastroenterologist-, and pharmacist-recommended brand to treat your frequent heartburn. to request a free sample, visit prilosecotc.com.